The present invention relates generally to conversion of sunlight into other forms of energy, including thermal energy and electrical energy, and, more particularly, to use of elongated concave trough-shaped reflectors connected in an array for unitary movement, and maintaining essentially perpendicularity between the reflectors and the rays of the sun to heat water with linearly-focused, reflected sunlight and to create electricity with point-focused reflected sunlight derived from the line-focused reflected sunlight.
Solar energy is freely and daily available. It is a clean, non-polluting source of energy. Providing a reliable, long term, cost effective, efficient way of using sunlight to obtain electrical and thermal power has long been an unsolved problem, until the present invention.
It has been proposed that flat panel solar converters be used to convert direct sunlight into thermal or electrical energy.
Pedestal supported flat panels using direct sunlight to generate electricity were part of the Solar One project.
A circular, but concave reflector mounted on a single column or pedestal has been proposed. This approach was used on the Soler as water desalination project in Saudi Arabia and on the Solar Two project in Dagget, Calif.
Fixed position concave reflectors placed in an array and positioned in side by side rows on an incline have been proposed. See U.S. Pat. No. 4,202,322. Such an installation was made at the Federal Correctional Institution at Phoenix, Ariz.
Tiltable elongated concave reflector assemblies have been utilized, such as the one at Barstow, Calif., owned by FPL Energy SEGS VIII and IX.
Solar Systems comprising bidirectionally controlled Fresnel lens and solar cell assemblies, utilizing direct sunlight, have been proposed. See, U.S. Pat. No. 4,649,899, for example. Also see, U.S. Pat. No. 4,245,153. Optical detectors for dual axis tracking of the sun are known.
The above-identified proposals and installations have failed to provide reliable, low cost, efficient, variable capacity systems by which solar energy is converted to thermal and/or electrical energy. A long felt need has existed for energy conversion plants which are reliable, efficient, cost effective and size variable to meet both low and high capacity demands for thermal and electrical energy.
In brief summary, the present invention overcomes or substantially alleviates the long term problems of the prior art by which solar energy is converted to thermal energy and/or electrical energy. The present invention provides reliable, cost effective systems for such conversion, where the size of the system can be correlated to the desired capacity.
The orientation of an array of elongated concave parabolic trough-shaped reflectors is biaxially kept essentially perpendicular to rays of the sun by a control such that the sunlight is reflected and concentrated along a focal line of each elongated reflector by which (a) tube-contained water is heated at the focal line by reflected sunlight impinged thereon and/or (b) line focused reflected sunlight is optically transformed into point focused reflected sunlight from which electricity is generated using solar cells upon which the point focused reflected sunlight is impinged.
With the foregoing in mind, it is a primary object of the present invention to overcome or substantially alleviate the long term problems of the prior art by which solar energy is converted to thermal energy and/or electrical energy.
Another paramount object of the present invention is to provide reliable, cost effective systems for such conversion, where the size of any such system can be correlated to the desired capacity.
A further object of great significance is the provision of solar energy conversion systems wherein the orientation of an array of elongated concave parabolic trough-shaped reflectors is biaxially kept essentially perpendicular to rays of the sun by a control such that the sunlight is reflected and concentrated along a focal line of each elongated reflector by which (a) tube-contained water is heated at the focal line by reflected sunlight impinged thereon and/or (b) line focused reflected sunlight is optically transformed into point focused reflected sunlight from which electricity is generated using solar cells upon which the point focused reflected sunlight is impinged.